performance
through thickfolds
approaching climate-responsive behaviours through shape, materialisation and kinematics
Torsten Sack-Nielsen
Submitted to
the Aarhus School of Architecture in partial fulfilment of the
requirements for the degree of Doctor of Philosophy in Architecture
performance
through thickfolds
approaching climate-responsive behaviours through shape, materialisation and kinematics
Torsten Sack-Nielsen
Submitted to
the Aarhus School of Architecture in partial fulfilment of the
requirements for the degree of Doctor of Philosophy in Architecture
PREFACE
Summary (English and Danish) Acknowledgement
I FOUNDATION
01 Introduction 02 Methodology
II FIELDS
03 Performance through folding 04 thickfold
III TESTING
05 xp1_performance through shape change 06 xp2_performance through materialization 07 xp3_performance through self-actuation
IV SYNTHESIS AND DISCUSSIONS 08 Synthesis and discussions Bibliography and photo credits
4 11
12 38
54 86
126 172 198
228 256
TABLE OF CONTENT
PREFACE
SUMMARY [ENGLISH]
Performance through thickfolds1
approaching climate-responsive behaviours through shape, materialisation and kinematics.
Addressing adaptive solutions to architecture requires responding to a changing climatic environment instead of statically resisting it.
As the demands on the performance of contemporary buildings and their climate-skins are increasing, new alternative, eco-effective and resource-saving approaches are essential. The ability of adaptation opens - like in nature - the perspective to optimise climatic behaviour within a given local context.
The principle of folding contains dynamic aspects with the capability both to adjust shape through its changing geometry [form] and the specific movement embedded in the fold pattern [kinematics].
In this PhD project, folding is investigated phenomenologically, exploratively as well as experimentally, to exploit and document on how climate-responsive performance potentials can be utilised in architecture. ‘Origami technology’, as the emerging, cross-disciplinary field behind it, transfers principles from the ancient art of paper folding into sophisticated design applications.
The project proposes an initial concept, which was developed through explorative design studies, to preserve the foldability of the material despite the thickness of a (sandwich) panel. It is referred to as the thickfold concept.
Performance aspects are empirically investigated in three main test series which focus on shape [change], materialisation and self- actuation. The methods of investigation cover dynamic computational simulations, climate laboratory tests and material tests for thermo- responsive behaviour.
In summery, this project identifies and indicates climatically beneficial aspects based on the dynamic principle of folding and through the materialisation towards a thickfold.
1 The notion of thickfold in this project is defined as: Thick, rigid foldable material entity, with a thickness of a plate or sandwich element.
This PhD thesis consists of eight chapters, which are gathered into four main sections:
FOUNDATION (01-02), FIELDS (03-04), TESTING (05-07) and SYNTHESIS + CONCLUSIONS (08)
To introduce and frame this research topic, the principle of folding is employed and later utilised for dynamic climate-adaptability.
01 ‘Folding’ is contextualised phenomenologically and the potential of combined morphological and kinematic abilities is explored.
State-of-the-art examples in architecture display the recently built development of these concepts. The drivers for this investigation – dynamic performance and multi-functionality - lead to the hypothesis of performance through thickfolds and the research question, linking the dynamic capabilities of folding to the aspects of shape, materialisation and kinematics.
02 A mixed-method approach characterises the project and is elaborated on in this chapter. Through the explorative method of research- through-design, folds were created and tested in hands-on studies.
These folded objects laid the foundation for a systematic evaluation regarding geometry, kinematics and performance potentials.
One selected fold (Miura-fold2) was subsequently developed further with an applied thickness and comparatively studied with cardboard models. Empiric-analytical methods connect on each of the three topics to measure, analyse and document performance regarding climate- responsiveness quantitatively. These methods include: computational simulation, climate laboratory tests and material testing.
03 The work with folding principles is framed within the recent development and scientific field of ‘origami technology’, which transfers principles from the ancient art of paper folding to contemporary technical solutions.
To demonstrate alternative adaptation principles through folded morphology, plants in extreme climates are exemplified in a literature review. These species support the hypothesis as ‘approved’ examples.
A matrix [1] systematically collects and maps the range of beneficial performance aspects for 53 folds with references to architectural scale, kinematic applications, biomimetic references and related industrial designs. A second matrix [2] evaluates the paper folds regarding their geometrical and kinematic properties.
04 Subsequently the selected Miura-fold is explored, investigated
2 The fold is named after its inventor Koryo Miura, a Japanese space scientist, who developed this fold pattern.
and developed through design studies to approach thickfolds. These folds evolve from ‘immaterial’ thin, kinematic artefacts to foldable structures with a materialised thickness. A centred textile layer within the thickfold-element is introduced providing the ability to fold without hinges.
The three primary test series 05-07 empirically investigate the enhanced potentials.
05 The first test series xp1 focused on performance through shape
[change]. A dynamic, computational simulation series based on a specifically developed script of Rhino/Grasshopper3D and Ladybug examined the thickfold’s behaviour during the effects of various solar irradiation impact over the year. In 124 situations, different compression states of the folds, orientation and point in times were tested. This resulted in visual models, as well as, numeric results.
The outcome, which is evaluated in nine excerpts, identified specific patterns and tendencies of passive solar performance on the folded surface in dependence of the dynamic behaviour.
06 The second test series xp2 addresses performance through materialisation. The centre layer of the thickfold assembly becomes the objective, investigating the potential of activating the layer climatically. The textile transforms here in combination with water from a passive material layer into an interfacial, active agency for cooling purposes. In a test setup at the climate laboratory of Navitas, Aarhus University, two climate chambers with moisturised textile membranes in 31 combinations were tested regarding their cooling capacities. The measured data of both humidity and temperature levels were comparatively analysed. In conclusion, the principle of active [evaporative] cooling for textiles could be validated and documented for distinct variables, such as the effect of size, geometry and shape.
07The third experiment series xp3covers the topic of the performance through [thermo-responsive] self-actuation. Actuation principles are introduced as the autonomous response behaviours of materials to climatic changes. They could serve in the future to climatically control dynamic elements.
Thermobimetal was chosen for the test series. 54 identical samples were modified with individual micro patterns, laser cut by a waterjet, to investigate the effect on the kinematic ability.
Under the impact of heat, the application of patterns to the bimetal led to different thermo-responsive movements. It furthermore proved that it was possible to adjust the kinematic behaviour through the application of form, in this case patterns. In perspective, this
‘programming of sensitive material’ can lead to tailored, customised self-actuated elements.
08 Finally the primary results of the different investigations based on the principles of folding and the concept of a thickfold document that
• form can be utilised for a beneficial passive performance
• material can be utilised for an active performance
• self-actuation can be utilised for a responsive performance.
The investigations open up for further developments of combined, multi- functional and climate-responsive elements and a more performance- oriented utilisation of the folding principle in architecture.
A separate documentation book contains the extended description and the results of each of the test series.
SUMMARY [DANISH]
Performance gennem thickfold-konceptet
Klima-relaterede undersøgelser af form, bevægelse og materialer
Adaptive løsninger i arkitekturen forudsætter at man reagerer på de skiftende klimatiske forhold i stedet for at modvirke dem.
Eftersom behovet og kravene for bygningernes performance og deres klimaskærme stiger, er der brug for at finde nye og alternative, ’grønne’
og ressource besparende løsninger. Evnen til at tilpasse sig klimatisk giver – ligesom i naturen – mulighed for at optimere ydeevnen (performance) i forhold til omgivelserne.
Foldeprincipper indeholder forskellige dynamiske aspekter, når overfladen tilpasser sig gennem foranderlig geometri [form] og gennem den specifikke bevægelse som ligger i folde mønsteret [kinematik].
I ph.d. afhandlingen undersøges foldninger fænomenologisk, praktisk undersøgende og empirisk-eksperimentelt, for at dokumentere hvordan klima-relaterede potentialer kan overføres til arkitekturen og skabe nye muligheder.
Baggrunden for undersøgelsen er ’origami technology’. Dette nye, tværfaglige forskningsfelt overfører principper fra oldtidens papirfoldekunst til sofistikerede tekniske løsninger. Afhandlingen præsenterer et thickfold-koncept, som er udviklet og undersøgt gennem design studier, for hvordan et sandwich materiale kan foldes.
Den klimatiske ydeevne er undersøgt i tre forsøgsserier, som fokuserer tematisk på foranderlighed i form, materialisering og selvaktivering.
Metoderne som anvendes i undersøgelsen, er dynamiske computer- simulationer, forsøg i klima-laboratoriet og forsøg med termisk følsomme materialer.
Afhandlingen identificerer og udpeger klimatisk gavnlige aspekter baseret på dynamiske foldeprincipper og gennem materialiseringen til en thickfold.
---
Denne ph.d. afhandling indeholder otte kapitler samlet i fire hoved sektioner:
Grundlag (01-02), Områder (03-04), Forsøg (05-07) samt Syntese og konklusioner (08).
Foldeprincipper er det gennemgående emne i denne afhandling.
Principperne undersøges i forhold til den dynamiske evne til at tilpasse sig klimaet.
01 Foldning kædes sammen med de dynamiske potentialer, der opstår når man kombinerer de morfologiske (formrelaterede) og kinematiske (bevægelsesmæssige) evner. Der vises nye arkitektoniske eksempler som udnytter disse potentialer.
Dynamisk performance og multifunktionalitet som målsætning leder til hypotesen og forskningsspørgsmålet om ydeevnen gennem thickfolds.
02 De forskellige forskningsmetoder som kentegner projektet er uddybet i dette kapitel. Studier med foldeprincipper undersøges gennem research-through-design. Disse folde-objekter danner grundlaget for en systematisk evaluering i forhold til geometri, kinematik og ydeevne.
Som udvalgt foldning, bliver Miura-Ori efterfølgende studeret i fysiske modeller med en tilføjet tykkelse. Empirisk-analytiske metoder bliver anvendt for at måle, analysere og dokumentere performance gennem dynamiske computer simuleringer, målinger i klima laboratoriet og materiale tests.
03 Foldeprincipperne uddybes og sættes i relation til forskningsfeltet
’origami teknologi’, som oversætter origami i nutidige tekniske løsninger.
Der refereres til eksempler fra naturen, som har tilpasset sig ekstreme klimaforhold gennem deres foldede ydre. Deres morfologi understøtter hypotesen som ’afprøvede’ eksempler. I Matrix 1 er 53 folde-objekter systematiseret med reference til arkitekturens skala, bevægelsesmønstre, biomimetiske referencer og industriel design.
En yderligere Matrix 2 evaluerer folde-objekter i forhold til deres geometriske og kinematiske egenskaber.
04 I kapitlet undersøges Miura foldningen nærmere og videreudvikles som en ’thickfold’. (Papir)foldningen udvikler sig fra værende immateriel til at blive til en foldbar struktur med materialets tykkelse.
Et tekstil lag, som placeres i midten af thickfold-elementet, bliver introduceret, så strukturen bliver foldbar uden hængsler.
De tre primære forsøgsserier undersøger empirisk performance potentialerne:
05 Den første forsøgsserie xp1 fokuserer på performance gennem (foranderlig) form. En serie af dynamiske computer simuleringer, baseret på et script fra Rhino/Grasshopper3D og Ladybug, undersøger hvordan en thickfold reagerer i forhold til solar indstråling i løbet af et år. Forskellige geometriske varianter af foldningerne, orientering og tidspunkter bliver testet i 124 forskellige situationer. Resultatet er visualiserede modeller og numeriske resultater, som er evalueret i 9 uddrag. Disse identificerer specifikke mønstre og tendenser i forhold til den passive solar performance som foldningens overflade har.
06 Den anden forsøgsserie xp2 undersøger performance gennem materialisering. Det midterste tekstil lag i en thickfold bliver undersøgt, med henblik på at se hvilket potentiale der opstår, når tekstilet bliver aktiveret klimatisk. Når tekstilet tilføjes vand, forandrer det sig fra værende et passivt materiale til et kølende element.
I forsøgsserien, som blev udført i klima laboratoriet i Navitas, Aarhus Universitet, blev to klima kamre med 31 forskellige tekstil kombinationer undersøgt i forhold til deres kølende effekt. Resultaterne fra målingerne i form af data for luftfugtighed og temperatur bliver analyseret. Konklusionen er, at princippet med aktivt kølende tekstiler, afhængig af størrelse, geometri og form kan valideres og dokumenteres.
07 Den tredje forsøgsserie xp3 undersøger performance gennem (termisk sensitiv) selvaktivering. Forskellige principper for klimatisk selvaktivering af følsomme materialer introduceres. Fremtidigt vil disse materialer kunne styre dynamiske foldestrukturer klimatisk.
Termobimetal er valgt til denne test serie. 54 identiske prøver bliver modificeret med forskellige mikromønstre, som er skåret ud med en waterjet laserskærer, for at undersøge effekterne på den termiske reaktion. Under varmepåvirkning viser prøverne en ændring af bevægelsen. Yderligere påviser prøverne, at det er muligt at justere en termisk bevægelsesadfærd gennem mønstrene. For fremtiden kan denne ’programmering af temperatur-følsomt materiale’ føre til skræddersyede bevægelser for selvaktiverede elementer.
08 De primære resultater af undersøgelserne, som er baseret på foldeprincipper og thickfold konceptet dokumenterer følgende:
• at foldet form passivt kan forbedre dynamisk klima performance
• at materialet aktivt kan bidrage til klima performance
• og at interaktiv selvaktivering kan tilpasses til klima performance
Undersøgelserne som er gennemført i dette ph.d. projekt åbner op for en videreudvikling af princippet med kombinerede, multifunktionelle og klima-(inter)aktive elementer og en mere målrettet benyttelse af foldeprincipper i arkitekturen.
Bog II indeholder dokumentationens samt resultater og beskrivelser fra de enkelte test serier.
ACKNOWLEDGEMENT
I would like to thank my supervisors Inge Vestergaard and Walter Unterrainer for their valuable critics and comments through the process of the PhD project, my PhD fellows as well as all involved teachers during the biannual VIVAs for their feedback. In general thanks to AAA´s administration and the PhD school for supporting the project, with name Johan Verbeke and Hanne Gjelstrup.
Furthermore I would like to thank Pawel Tuchakowski for his support and advice on virtual scripting the dynamic computational model, Tim Merrit for his assistance at the waterjet cutter, Thomas William Lee for his assistance with the preparations of the Arduino micro-controller for the climate chamber test series, as well as Steffen Petersen from AU for kindly letting me conduct the test series at the climate laboratory of Navitas. I would also like to thank Stefan Hammer from the University of Weimar for his support on advanced structural calculations.
A special thanks I would like to address to Ulrich Knaack, Tillmann Klein and Holger Techen for the kind opportunity to stay and work as guest researcher at the department AE+T/TU Delft [NL] in spring 2015, including the possibility to participate at the subsequent biannual façade research group [FRG] meetings with fruitful discussions and critics in Delft, Darmstadt and Copenhagen. I am very grateful for the financial support, which I received with the grant from Knud Højgaards Fond to make this stay in Delft possible.
Furthermore I would like to thank for the gracious support from the industry, such as Auerhammer GmbH, Fiberline, MDTtex, Tesa, 3M, with sponsored materials and documentation.
And last but not least and most of all I would like to thank my parents, my parents in law and my dear family, Lene, Tilde and Silas for their
great support and understanding.
FOUNDATION starts out with an introduction 01, which is framing the research topic around the principle of folding and the utilisation for dynamic climate-adaptability. State-of-the-art examples of folding references in architecture conclude gaps as well as potentials. For the approach to achieve dynamic behaviour through folding, the drivers of investigation are introduced, subsequently leading to the hypothesis of performance through thickfolds including the research question.
01 introduction
FOUNDATION
01 introduction
FRAMING THE THESIS
THE PRINCIPLE OF FOLDING FOR ARCHITECTURAL SOLUTIONS
Climate-responsiveness in architecture Static versus dynamic
Approaching dynamic facades Folding beyond ornamentation
One geometric principle – many benefits Origami applied to architecture
Contemporary architectural examples
THE DRIVERS FOR THE INVESTIGATION OF DYNAMIC BEHAVIOUR
Performance
Layered multi-functionality Materialisation of folds
HYPOTHESIS AND RESEARCH QUESTION Hypothesis
Main objectives and research question Bibliography
FRAMING THE THESIS
The PhD thesis is based on the principle of folding. Through morphological1- geometrical investigations, the dynamic behaviour of folded structures are explored and analysed with the purpose to adapt to climatic impacts on the surface.
With my background and interest in innovative ‘green’ solutions (facades), I sought for new approaches to improve performances of building skins through simple, low-tech principles.
Accessing the field of geometry throughstudies of ‘folding’ opened up for a range of dynamic potentials, which could serve future architectural applications.
Seen from a phenomenological point of view, folding contains and combines various beneficial ecologic, economic, technical-functional, socio-cultural aspects. These benefits can probably be transferred and utilised for the purpose of an ‘eco-effective’ 2 performance:
Folded geometry turns basically a sheet of material into a structural entity. The principle of folding adds structural strength without adding material. Dimensions of constructions or elements can be reduced and subsequently material, as well as weight, can be saved [material efficiency].
Secondly, a fold represents, in fact, a dynamic geometry with a changeable ‘body’ and surface. While the ‘body’ can follow various open-and-close states [flexibility], the subdivided fold pattern turns through motion into a multi-angled surface. The change of shape embeds the potential to adjust to the local premises or even to interact with the context [adaptability]. Through this adaptive behaviour, beneficial performance can be tailored based on the design to vary, minimise or maximise impacts on the folds [e.g. in regards to comfort aspects or resource savings].
Referring to the origin of a paper fold, a hingeless and purely material- based structure can be detected, just based on the fold lines of the
1 Morphology is the study of the form or structure of anything (source:
dictionary.com)
2 The notion ‘eco-effectiveness’ is used in contrast to ‘eco-efficiency’, in which the ‘green’ strategy is not just based on a reduction of a harmful effect, but on a positive increase of value. (Guldager and Lyngsgaard 2013:14)
geometry/pattern. Transferring this principle into materialised versions, foldable structures could be achieved without mechanical hinges. In consequence could this lead to more simple kinematic and much less maintainable architectural solutions [probably both economically efficient and durable].
And at last the fascination for the variable expression of geometry and playfulness of changing patterns has to be emphasised, which in this case intend to link and interweave aesthetics visibly with dynamic performances [visual and aesthetic quality].
THE PRINCIPLE OF FOLDING FOR ARCHITECTURAL SOLUTIONS
Folding has to be seen beyond the ancient Japanese art of paper folds. The techniques are nowadays transferred to mathematics and computer science. But in particular interesting for this project is the emerging field of product applications and folded solutions for engineering purposes. The field of applied folding, also called origami technology, got lately additional attention as NASA proclaimed ‘large aperture deployable systems’ in an open research call 2012 as major investigation area. The American space agency included the field in their research program as one of their “game-changing opportunities in technology development”(NASA 2012).
Nevertheless, anticipating folding for future developments can be dated far back to the 1920s. Already in 1928 L. Moholy-Nagy points
fig. 1.1
A tesselated paper fold and its kinematic ability to unfold
potentials for folding studies out in his book “The new visions”.
Referring to the work with students of both teacher Joseph Albers, who taught at the old Bauhaus and teacher Hin Bredendiek at the new Bauhaus (1937), he expressed his hope for inventions in the future of building construction:
“These activities [red. cutting and folding], I hope, will be the source of a great number of inventions for building constructions, household appliances, packing, book binding, etc. The problem here will be, of course, as everywhere else, to find the right ways of application.
Here the importance of the elements will not be dominant but happily absorbed through the best solution of the necessary function. “
(Moholy-Nagy 1947:54)
Still today after 70-80 years Moholy-Nagy´s statement seems to be very relevant and valid. The potentials do not appear to be fully exploited yet, especially considered in regards to the folding principle of thickened material and regarding dynamic performance.
A synergetic linkage between geometric principle and materiality - means and matter - were the focus of interest for this project to aim for more simple dynamic solutions for building skins.
Simplicity and cost-efficiency of the foldable structural elements should lead in the end to possibilities of mass production and a broad use of a measurable positive impact on the environment.
The principle of folding has obviously three potentials for dynamic behaviour:
First of all folding embeds the capacity to change shape due to its kinematic nature. Secondly, in the process of materialising zero- thickness folds3, material properties enable further opportunities to adapt and react to climatic conditions. Activation of layered, but merged materiality and new types of multi-functional materiality applied to materialized folds opens up for responsive behaviour.
And third, the actuation of the folding movement could be linked to climatic preconditions. Material-embedded shape- or volume- changing properties, caused by climatic stimuli, might be the motor for a self-actuating behaviour.
3 Paper folds are considered zero-thickness as they are mathematically not taking material thickness into account
In this project dynamic [responsive] behaviour with folded matter through geometry is approached and investigated by each of the 3 topics of: shape, materialisation and kinematics.
Shape Variation in angled surfaces of
tessellated folded structures allows distinguishing between purposes for the different facets. Advantage can be taken of the range of impacts on the surface and performances can be utilised. The surface area can vary in size and exposure, which could actively be used to provide dynamic behaviour e.g. for building skins.
Materialisation The alternative approach allows thickfolds to be built in new ways. The folded structure can be materialised more or less independently of its thickness. Multi-functional properties can be added. The resulting thickfold can vary in transparencies, porosities, sizes, surfaces, layered materiality and more.
Kinematics The fold pattern does not only define a 3-dimensional surface with a linked specific kinematic behaviour but aims in this case for a self-actuated material-embedded movement. Tests are conducted with thermosensitive material to achieve tailored zero- energy movement. By applying various patterns to the material samples, a control and variation of the movement is intended.
Folding in architecture as a purpose beyond ornamental and aesthetical premises is often found in structural designs utilising the efficiency of the folded shapes and the simplification of complex multi-curved surfaces. In this research, the folding principle should go beyond purposes of static, non-movable applications. The aspect of kinematics
combined with the dynamic performance of foldings should enable our buildings to become responsive.
“Nie zuvor hatten wir eine so große Chance, Architektur jenseits des Irrglaubens an eine totale räumliche und klimatische Kontrolle in der Wechselwirkung von Material, Struktur und Umwelt zu entfalten”4
(Hensel and Menges 2008:16)
Climate-responsiveness in architecture5
Buildings play an important role in global energy consumption, as they account for approximately 40% of the energy use in most countries.6 Poorly performing building envelopes can be affiliated as one of the reasons. Improving and rethinking building envelopes embeds a significant potential for saving energy and resources.
Building envelopes can be in general considered as rather static boundaries: Resisting, protecting and separating7 the interior space from the outside (Knaack, Klein, and Bilow 2007:15). Façades are here the interface where interior and outdoor climate meet, with all the demands regarding building physics such as weather protection, insulation, ventilation, humidity, light control, etc. to provide best possible user comfort. The development of façades in the past followed the idea consistently of separating these conditions. The interior was disconnected and separately conditioned for the purpose of achieving a fully controlled stable interior environment with a high effort of energy and technical support.
A promising way of approaching alternative façade designs is one that exploits the potential of adapting dynamically to the various climatic conditions.
4 Accordingly translated: “Never before we had beyond the heresy for a total spatial and climatic control such a chance to unfold architecture in the interaction between material, structure and environment.”
5 The introduction is based on the conference paper: Approaching climate- adaptive facades with folding (Sack-Nielsen 2014)
6 IEA 2010. “Energy performance in buildings”, p.5
7 see also Knaack, U, Klein, T & Bilow, M 2007, Imagine 01: Facades, 010 Publishers, Rotterdam, pp.15. “(…). The main function of a façade
is the separation of the outside and inside climates to supply a certain quality to the enclosed volume. (…)”
The building envelope develops with this from a protection layer into an interaction layer. The façade becomes responsive. Inside and outside conditions are not seen as contradictions but rather as environments with a natural interaction. Ideally, the façade takes advantage of the differences and reacts dynamically to improve the indoor conditions.
The interior and the exterior are in a symbiotic relationship through the mediating façade layer and reduce the negative impact on the interior environment.
This approach follows not only a ‘romantic’ utopian wish to seek a closer relationship with nature, but offers a real potential to save energy as well as enhance user-comfort significantly. The potential is documented in research projects such as “integreret regulering af solafskærmning, dagslys og kunstlys”8 (Johnson et al. 2011:7). In this research, the potential of only (electrical) energy savings regulating dynamic sun shading systems is quantified by 5-20%. Additional benefits of adaptive façades are furthermore to find in comfort aspects related to light control, heat gains, ventilation and so on.
Beyond energy savings Hausladen et al. argues of the dynamic principle as a comparison with skin or clothing, which can be changed regarding the current climatic situation. They embed both the principle of separation and exchange, depended on the situation.
Transferred to building skins, materials would have to fulfil multi- functional purposes at the same time.
“Als dritte Haut des Menschen muss die Außenhülle des Gebäudes ähnliche Aufgaben erfüllen wie die Haut oder die Kleidung. Diese schaffen ein Innen und Außen, trennen, sind aber durchlässig, sodass ein Austausch möglich ist. Dies kann nur gelingen, wenn die eingesetzten Materialien der Gebäudehülle viele Hautfunktionen erfüllen können.”
(Hausladen et al. 2006:14ff.)9
Complementary to architecture, Moholy-Nagy introduced in the 1920s his kinetic sculptures as a dynamic principle in art and mentioned the
8 transl. “integrated regulation of sun shading, daylight and artificial light”
9 Hausladen, G, De Saldanha, M & Liedl, P 2006
transl.”(…) As the third skin of humans, the building envelope has to fulfil tasks as skin or clothing. These create an inside and outside,separate, but they are permeable so that an exchange can occur. It is only possible if the used materials of the building skins fulfil many skin functions. (…)”
fig. 1.2
Clothing as analogy for climate adaptability
significance of material within a construction exceeding form, but acting furthermore as an agency to provide a dynamic behaviour or as he expresses: carrying [distributing] forces.
“We must, therefore, put in the place of the static principle of classical art the dynamic principle of universal life.
Stated practically: instead of static material construction (material and form relation), dynamic construction (vital constructivism and force relations) must be evolved, in which the material is employed as the carrier of forces .”
(Moholy-Nagy 1947:138 [orig. 1928]) (Agkathidis and Schillig 2010:9)
Static versus dynamic
Kemp and Fox argue for a dynamic approach to kinetic structures by pointing to the negative consequences of a static approach. Static architecture would have to withstand for all conditions with the same design. The result would end over-dimensioned and inefficient for most cases.
“With static architecture, we typically must overengineer our buildings to account for worst-case scenarios of structural failure.” (Fox and Kemp 2009:47)
This could also be assigned to a dynamic system, which would have to control an external climatic environment. While a static system, separated from the exterior, would have to resist the highest impact, an adaptive system could reduce negative or undesired effects through active interaction.
Taking the infinite amount of different possible impacts into consideration, it is hard to imagine that one single fixed solution would be able to cope with all possible situations in an effective way. Or as Lechner said to his students:
“It is illogical to believe that a static solution can respond to a dynamic problem.” (Lechner)10
Seeking for environmental optimisation to reduce resources of material and energy will naturally end in investigations and designs of dynamic solutions.
10 Lechner, R 2014. A personal quote from a lecture at Auburn University, USA
Approaching dynamic facades
Early and simple examples of adaptive façades can be found likewise with vernacular wooden shutters. Referring to the example in Bressanone [fig 1.3] this solution offers various multi-functional states and positions of the wings of the shutter to regulate comfort and visual transparency. While in a closed position the element still acts as a permeable screen, which allows cross ventilation on warm summer days with open windows, the lamella frame provides sun protection without compromising natural daylight. The angled lamella furthermore enables the visual connection to the street even when the shutters are closed. In winter situation the wind protected buffer zone contributes to reduced heat loss through the window at night. Open states instead provide the full transparency and visual contact to the outside with a maximum gain of natural daylight.
In 1983 gave Jean Nouvel the dynamic principle a novel façade expression. His façade design for the “Institute du Monde Arab” in Paris can be seen as one of the key projects for the newer adaptive façade development.
This architectural example demonstrated very powerful on how adaptability as a concept could be realised and displayed in a façade.
The ingenious approach transferred traditional Islamic patterns and perforated ornamented screens into an advanced technological façade expression and functionality. Qualities to alter light conditions in the interior are achieved with the principle of adjustable apertures of (camera) iris diaphragms11 triggered by photo-sensors and actuated by motor-mechanism [fig.1.4].
Despite the fact that the façade design has an undeniable value, a broader spread of similar adaptive designs did not occur. High maintenance and construction costs combined with high failure rates due to the fragility of the sensitive mechanical system turned this approach, unfortunately, it into an exclusive niche product for small amounts of customers.
More recent examples show dynamic facades providing climate- adaptive behaviour through explicitly utilising changing geometries.
Two projects work with rather similar principles of triangulated shading elements: Kolding Campus [SDU] by Henning Larsen architects from 2014 and the ThyssenKrupp headquarter in Essen by JSWD architects and Chaix & Morel et Associés from 2010.
Henning Larsen architects covered the glass façade of the university
11 Iris diaphragms are adjustable optical apertures in photographic lenses fig. 1.3
Close-up of a traditional wooden shutter in Bressanone, Italy fig. 1.4
Close-up on the mechanical aperture system of the facade at the Institute du Monde Arab, Paris by Jean Nouvel fig. 1.5
Close-up of the outer facade of SDU, Kolding, by Henning Larsen Architects
fig. 1.3
fig. 1.4
fig. 1.5
building with triangular shutters of perforated steel as an additional sun protection layer [fig.1.5]. The elements are also here, like at the Institute du Monde Arab in Paris, individually motorised and regulated by sensors measuring heat and daylight. The rotating movement outwards and the individual mechanical actuation enables infinite states of adaptation between the demands of visual comfort, interior daylight condition and control of heat gains through the façade.
A similar principle was used at the façade of the ThyssenKrupp Headquarter in Essen but with the difference of tight horizontal stainless steel lamellas instead of the perforated steel. Both approaches provide transparency even at closed conditions.
Beside the functional purposes of regulating the solar impact, the visible interaction and of the façade in regards to climate conditions adds a strong and powerful expression to the façade. This is also in these cases a strong argument of additional value for the client to justify the rather high additional construction costs of a motorised kinetic façade.
The PhD project continues on the idea of dynamically and visibly change performance. However, it questions the means and intends to explore (explicitly) alternatives to a technologically advanced, mechanically complex, and sensor-driven high-tech solution to approach dynamic building skins. Instead, a principle is proposed to study and investigate dynamic potentials by folding.
Folding beyond ornamentation
Folding as objective in the thesis is neither considered or developed from a visual or artistic point of view nor approached in a formalistic manner. The basic dynamic geometrical principle of folding is the base for the investigation to enhance climate-responsive performance.
With a proper understanding of dynamic influences towards building performances and comfort, supported by recent advanced simulation tools and control mechanisms, dynamic behaviour can be addressed and designed to the function. The visual appearance of folded and foldable surfaces in architecture as ornamentation is transferred to adaptable shapes of functional adaptive patterns, which are optimised in their function and developed to contributes beneficially with their shape beside the aesthetic value. Selected and very recent built examples with expressively folded or foldable building skins demonstrate the state-of-
the-art in façade design, where shape and dynamic behaviour reaches beyond ornamentation, and form generation follows performance.
One geometrical principle – many benefits
An exemplarily good example of a beneficially embedded folding principle in architecture, leads far back to industrial architecture in the 19th century. Even so static, saw-tooth roofs of industrial buildings can be understood as built examples of basic zigzag or one-crease origami folds (Reis, Jiménez, and Marthelot 2015:12235).
The ‘folded’ roof as a fifth façade was in this typology designed to exploit and serve additional purposes. The geometry became an integral part of the design and transformed the roof from a pure weather protection layer into a multi-functional element of the envelope. While one angled row of segments provide self-shading and glare protection from direct sunlight, the opposite band of windows -optimally oriented towards north12- supplies the space underneath with additional indirect natural daylight. The triangular shape of the roof section furthermore supports natural ventilation through increased height of space and geometry.
Structurally the construction of trussed beams can be embedded within the triangular inner space with no extra demands for additional room height.
For the application of photovoltaic modules on the roof, the rows of angled surfaces turning south provide optimised conditions for higher efficiencies of the solar panels compared to flat roof surfaces.
These multiple single benefits add in the combination a better performance for the architectural space, based on passive design principles, with improved comfort, enhanced aesthetical value inside and outside, improved natural daylight situation, natural ventilation, and benefits for solar energy installations. In the same mindset, a thickfold-approach could be applied to façade designs.
Even though the principle of a saw-tooth roof and the advantages are commonly well-known, this typology demonstrates quite strongly the potentials of folded morphologies in architecture. The multi-functional design based on a static, constructed fold can act beneficially in several
12 In the case, the vertical roof glazing would be oriented to the south, the variation of sun angles in summer and winter situations would still allow adapted solar gains. A cantilevered roof extension over the glass band would furthermore reduce direct sunlight in summer and still allow full direct daylight in winter at low sun angles.
fig. 1.7
The Resnick Pavilion’s sawtooth roofline fills the interior with diffuse natural daylight.
fig. 1.6
Showers center, Bloomington, with a former industrial sawtooth roof.
ways regarding comfort and passive energy saving solution.
The possibilities in an adaptive, kinematic application could be even more beneficial. Using and transferring these surplus design principles into a vertical façade application could lead to new multifunctional building skins.
Origami applied to architecture
The principle of folding can combine advantages of applied geometry and visual appearance for façade applications in architecture.
Geometrical surfaces can be calculated, simulated and optimised for performance advancements, while the expression of folding with its sharp, repetitive and three-dimensional patterns achieve a strong visual effect. Changing daily and seasonal light conditions shift the appearance of light and shadow on the surface for the spectator constantly.
Origami, the art of folding, can be found realised in different ways and on different levels applied to facades.
Many architectural references focus purely on the visual effect and folding as a principle was superficially used as decoration. This is especially the case for many glass curtain walls where the fold is more or less reduced to a simple representation with no specific tectonic need or advantage for the performance. Other examples, in turn, use the additional performance values of the folding principle for the façade design.
Reis et al. used three categories to distinguish origami-inspired structures:
(i) origami-looking, (ii) origami shaped,
and (iii) deployable (that use origami patterns)”
(Reis, Jiménez, and Marthelot 2015:12235)
While the first category (i) follows a pure formal expression, the origami shaped examples (ii) use the potential of real folded structure for lightweight construction and additional benefits. The last category (iii) embeds additionally kinematic behaviour to react and achieve responsive behaviour with the surrounding. The motion and characteristics of the original paper folds are translated into thickfolds.
Built examples of architecture in the third category are mostly to find at advanced solar shading systems for facades.
Contemporary architectural examples
Biomedical research centre, Pamplona, Spain [2013]
Architects: Vaillo & Iriaray + Galar
The biomedical research centre with its characteristically folded façade is situated in Pamplona in Spain.
Vertically folded elements of perforated aluminium panels cover the glass façade of the laboratory building. Over the full height and a length of one hundred meters these self-supportive and triangulated V-shaped elements [4,5 x 0,8 meter] are alternately assembled and create visually one continuous V-crease-pattern of the aluminium screen as a second skin.
Transparency for the vision from the inside is achieved with the tight micro-perforation of the folded panels. As the panels are attached with a distance to the façade, natural ventilation is provided. The
fig. 1.8 (i)-(iii)
The references examplify the differentiation between the three origami-inspired categories
(i) (ii) (iii)
intermediate area creates a climatic buffer zone, which stabilises temperature fluctuation. The folded screen is in its fixed position constantly self-shading the façade, and the angled aluminium surface reduces heat gains by reflection.
This building skin achieves in its repetition of a simple folded V-shape element a geometrical complexity and a strong visual expression and identity. The folding principle provides here directly structural strength of the elements, which allows managing without an additional substructure, as well as functional advantages with solar shading for comfort and energy consumption.
Interesting here are the earlier references of the kinetic façade of Kolding Campus [SDU] by Henning Larsen architects [fig 1.5] or the ThyssenKrupp in Essen from JSWD architects and Chaix & Morel et Associés, which lead back to the same fold pattern in a hypothetically flat extracted position of the Biomedical Research Center in Pamplona from Vaillo & Irigaray + Galar.
The individual movement of each shutter of the kinetic references in Kolding and Essen could be reduced to only a few actuators for a folded screen based on the same geometrical pattern with similar three- dimensional geometric results. The freedom of singularly controlling each shutter would, in this case, be undermined, but eventually, a cheaper and less maintainable foldable solution for the whole façade could achieve similar performance results. In an angled situation the SDU façade would be very close to the static version of the folded perforated screen of the reference project in Pamplona. (Popp 2013)
fig. 1.9
Origami-folded perforated metal as second skin. Biomedical research center Pamplona fig. 1.10
The corresponding paper fold reference of a V-fold
The showroom of the company Kiefer Technic and its kinetic shading system is situated in Bad Gleichenberg, Austria.
The aluminium-glass façade of the exhibition building is characterised by a foldable perforated aluminium sunscreen. Vertical rails in front of the aluminium frames of the 14 façade-segments embed the actuation with electrical motors and acts as an independent load bearing structure for the shading device. The 56 shading devices consist of a pair of 2 horizontally folded aluminium elements fixed both at the bottom and at the top of each window for both storeys. Infinite patterns for external expressions, as well as views to the outside, can be created in 30 seconds.
As the folds are horizontally placed, the elements work at the same time as a parapet, cantilevered horizontal sunshade and light shelf to redirect light to the upper interior ceiling. The shading elements act as a source for additional indirect sunlight and provide furthermore improved natural light conditions in the interior space, even when the shading device is blocking direct sunlight. The consumption of artificial light can be reduced and energy saved.
The kinetic shading system of the Kiefer Technic Showroom demonstrates the potential of a simple single-folded horizontal shading element, multiplied in a repetitive pattern over the façade, to be able to achieve multiple responsive façade expressions.
The individual control and differentiation of movement of each element allows the adaptability to a variety of purposes and fulfils a range of aesthetic as well as functional performances. (Giselbrecht 2016)
fig.1.11
Kinetic sunscreen with multiple positions and expressions, Kiefer showroom fig.1.12
The corresponding paper fold reference of a zigzag-fold
Kiefer showroom, Bad Gleichenberg, Austria [2007]
Architect: Ernst Giselbrecht + Partner ZT GmbH
29
The Al Bahar Towers are situated in Abu Dhabi in the United Arab Emirates. In order to face the challenges of placing a high-rise building in a hot, arid climate with the high solar gains, several energy saving strategies are implemented in the design. The rounded shape of the glass façade reduces the surface to floor area and with that the amount of heat gains. Instead of using the usual solar protection panes [tinted or highly reflective glasses] for the glazed curtain wall, this project was aiming for an external, but dynamic sun shield, which could both protect both from glare as well as reduce solar gains. The design of the dynamic sun shading system has its inspiration in Islamic architecture with the traditional element of the mashrabiya, which is a wooden lattice screen used on covered balconies. The second skin is in this tradition a permeable shade but has as well a strong aesthetical value for the façade with its rich repetitive ornaments.
The foldable pattern of the sun shading is tessellated in triangular elements of PTFE. These can individually be folded, actuated by an umbrella-like mechanism. The response of opening and closing the folded pattern is directly related to the radiation and the sun position.
Direct radiation is blocked to raise the interior comfort by avoiding glare genes and heat gains, while indirect light can penetrate and provide natural sunlight in the interior.
The kinetic façade example combines exemplarily benefits of a strong aesthetical expression -based in a tradition of the Middle Eastern architecture- as well as the observance of the latest energy and comfort demands in office high-rise architecture. (CTBUH 2016)
fig. 1.13
Advanced kinetic sun shading system based on origami folding pattern, Al Bahar Tower
over view f
olds (without scale). 140519 over view f
olds (without scale). 140519
overview folds (without scale). 140519 overview folds (without scale). 140519
overview folds (without scale). 140519 overview folds (without scale). 140519
ventilating blooming/
shape changing
filtering
selvshading surface/ less exposed to the sun
other products
temporary deployable structures
adaptive folding matrix// origami tesselated folds
folding pattern folded references bionic principles perception specific potentials kinetic behavior
fig. 1.14
The corresponding paper fold ref. of a waterbomb tesselation
Al Bahar Tower 1+2, Abu Dhabi, UEM [2012]
Architect: Aedas UK
The last two projects, Kiefer Showroom and Al Bahar Towers2, show powerful kinetic architectural examples of advanced sun shading systems. Common for both is the big effort put in motorization and mechanical construction to achieve the geometrical variation of the folding effects. The investment costs and the following demands for maintenance make these façade projects rather exquisite.
In order to move these kinetic [folded] solutions out from their exclusive niche-existence to a wider range of projects, more simplified solutions would have to be designed.
Taking starting point in bringing the simplicity of a basic [paper]fold principles back to advanced automated systems, mechanically hinged plates could be replaced with continuous materiality with applied fold lines designed for creasing. Static advantages of continuous folded structures could beneficially be taken into account. The visual appearance of look-a-like folds could be replaced with systems utilising the benefits of the original basic folding principle for dynamic behaviour.
All three mentioned examples show big size solution of folded elements applied to the façade. This leads especially in the kinetic versions to massive substructures and motorisation. Within the thesis, the scale will be discussed, as the principle of folding in minor dimensions, but still in robust and resistant versions, would avoid effort in construction and resources.
In following the drivers for further investigations of dynamic behaviour based on the folding principle are elaborated. This includes suggestions on how to approach and embed multiple dynamic behaviours within one principle.
THE DRIVERS FOR THE INVESTIGATION OF DYNAMIC BEHAVIOUR
Performance
As the aim of resource savings of both energy and material is the motivation behind the investigations, the notion of ‘performance’ is introduced. Enhanced performance through the dynamic principle should lead to beneficial solutions in regards to climate-adaptability.
The term ‘performance’ can be affiliated with different meanings (Performance | Cambridge English Dictionary 2016):
1. [entertainment] the action of entertaining other people by dancing, singing, acting, or playing music 2. [activity] how well a person, machine, etc. does a piece of work or an activity
Throughout the PhD thesis, the terminology of performance is used regarding the meaning of beneficial ability. Performance relates here directly to the enhanced capabilities through the implementation of foldable elements. The principle of folding is investigated and evaluated to add valuable properties to achieve a performance-oriented architectural design. Instead of favouring a maximum of freedom in the architectural design process and expression, performance-oriented design is about justifying the effort by the performance enhancement.
Grobman argues for three dimensions of performance in architecture:
the empirical, the cognitive and the perceptual (Grobman and Neuman 2012:10). While the empirical performance is to evaluate as physical data by computational simulations or measuring equipment, the cognitive and perceptual dimension are far more complex to grasp.
This project focuses on the empirical and measurable dimension of performance. However, the dynamic aspect is central and required a far more advanced and multi-faceted approach. The role of [adaptable]
geometry, as well as kinematic behaviour and materialisation of the folds, are selected as areas of investigation to enhance theclimatic performance for foldable architectural elements.
Layered multi-functionality
In the idea to increase [the dynamic] spectrum of performances towards climate-responsiveness with the folding principle, another notion is introduced: multi-functionality.
Selected materials or material compounds can fulfil several purposes at the same time. This ability makes them not only efficient but also effective.
As to be seen in the ideation scheme13 [fig.1.15], a sequence of steps consecutively adds performances to the origin of a sheet material, which transforms into a multi-functional responsive element. It occurs in the first step by adding supplementary abilities through a folding process to the geometry of the surface. In a second step materiality is utilised not only reactively, but also in an active way. The material becomes a medium for intervening and changing the surrounding microclimate. In the last step, the kinematic ability to adapt the shape is utilised. The sheet of material [compound]could then be considered smart [‘multi-functional’], as the shape as well as the functionality is modifiable. Implementing ‘smart’ material14 (Addington and Schodek 2004:79) offers the potential to be responsive to the environmental
13 The ideation scheme is based on the original graphic from (Sack-Nielsen 2014:732), fig.2 ‘Processing adaptability with folding’
14 (Addington and Schodek 2004:79) defined ‘…five fundamental characteristics, distinguishing a smart material from the more traditional materials in architecture: transiency, selectivity, immediacy, self-actuation and directness.’
sheet of raw material [1]
raw material folded + multifunctional materials applied [1+2+3]
raw material folded [1+2]
raw material folded + multifunctional materi- als applied + kinematics [1+2+3+4]
Process of gradually enhancing climate-responsive behaviour through folding interactive
[auto-responsive]
justpure material
adding + stiffness/ strength + 3D surface + ability to shading + acoustic capacity + enclosed cavities to insulate + enclosed chan- nels for flow
adapting + shape + acoustics + geometry + states + area + transparency + permeability applying
(material properties) + reflecting + insulating + storing + absorbing + air purifying + sensing
processline [t]
becoming interactive in the ability to sense the environ- ment and to adjust to it
active [multi-functional]
regardless [non-functional]
Scheme adapted from paper...
[shape] [materialisation] [kinematics]
passive [functional]
fig. 1.15 Ideation scheme Process of gradually enhancing climate- responsive behaviour through folding
changes, due to e.g. sensitive surfaces or material embedded reaction patterns which physically can be used for actuation purposes. The component can emerge from just being smart [multi-functional] to be tailored ‘intelligent’ regarding its auto-responsive behaviour.
Stacking and merging adaptable materiality in layers seems a promising way to approach a climate-responsive behaviour. The idea and vision of layered multi-functionality were already described in 1981 by Mike Davies in an article about an ideal ‘polyvalent wall’
(Davies 1981) [fig.1.16]. He called it ‘a wall for all seasons’. This ultra- slim façade construction embedded energy harvesting as well as layers of actively sensing and adapting glass technologies (Addington and Schodek 2004:166). Davies´ vision can be seen as ‘driving force for new façade technologies… over the last decades’ (Knaack, Klein, and Bilow 2007:89).
The surplus value of addressing multiple adaptive functions within one component can be summarised with the notion of ephemeralization, coined by Buckminster Fuller:
“The benefit of an active sustainable system is that it can intelligently combine the resources of a number of systems so that when working together, the individual elements or systems achieve more than the sum of their parts” (Fox and Kemp 2009:115)
Materialisation of folds
The PhD project investigates on how a merged [layered] materiality could be introduced, transferring the folding principle into materialised matter and providing dynamic behaviour.
Applying materiality to folding principle leads to the challenge of adding a physical thickness to a mathematically considered zero- thickness of a fold. It contains the task that design solutions had to be investigated and developed to enable thickened sheet material to become foldable and to provide a kinematic ability.
Solving foldability within the given materiality follows a tendency, described by (Fox and Kemp 2009:226) as ‘…the beginning of a paradigm shift from the mechanical to the biological in terms of adaptation in architecture can be seen as the end of the mechanics.”
This development opens for new approaches to dynamic architectural design and new fabrication technologies.
fig. 1.16
Schematic representation of the ‘polyvalent wall’
(Davies 1981)
HYPOTHESIS AND RESEARCH QUESTION Hypothesis
Starting with the motive and applying the principle of folding induces various valuable properties to a basic plane sheet of material. Folding does not only generate a 3-dimensional surface and applies form, but also adds a kinematic changeability to the flat material. Hinges are provided with the material itself, and movements can be tailored with the fold line geometry. Even tessellated, repeated folded patterns can conduct a multi-faceted surface motion.
Learning from nature by studying the purpose of folding principles in the context of the species [biomimicry], as well as contextualising folded design applications and performances in other fields, could open new perspectives on approaching dynamic facades.
Enabling [thin]folds to be materialised and jointly keeping the continuous nature, without mechanical hinges and without compromising the original kinematic behaviour, has the potential to transfer the basic dynamic properties of shape, material and movement into rigid applicable architectural solutions. The fold principle could be actively applied as kinetic structures to enhance climatic [building]
performance.
Main objectives and research question
To localise and utilise unused potentials for performance enhancements in future adaptive architecture, the principle of folding offers three major dynamic fields to be investigated: adjustable shape, active materiality, and responsive kinematic behaviour.
The primary research question is therefore formulated as such:
Research question
How can the principle of folding in the framework of shape, materialisation and kinematics multi- functionally and dynamically contribute to climate- responsive behaviours and enhanced performance?
Through the following investigations the Research Question is expanded with secondary sub-questions, specifically addressing aspects of the individual studies:
Sub-Research Questions
RtDHow do folded forms perform? Moreover, how can it be utilised?
Which aspects of performance can be enhanced through the dynamic principle of folding [opposite to a planar static materiality]?
Can “immaterial” paper folds be transferred into thickened, materialised folded structures, keeping their kinematic behaviour as a continuous materiality [without adding mechanical hinges]?
xp1 How much influence does foldable [dynamic] form have on the performance concerning solar irradiation?
xp2 Are textiles able to become an agency for active climate- adaptive behaviour?
Moreover, if so, how much is the effect?
xp3 How much can geometry in the form of applied patterns inform movement?
Moreover, if so, can these patterns be used to tailor thermo-responsive behaviour?
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